A small San Diego medical device company and a UCSD scientist believe they’ve come up with the solution to a problem that has long vexed people with diabetes: a device that constantly monitors blood-sugar levels without painful finger pricks or frequent maintenance.

GlySens is seeking permission from the Food and Drug Administration to launch a pilot study testing its implanted wireless sensor in about a dozen people with diabetes. The request came after researchers completed trials of the device on animals.

On Wednesday, University of California San Diego bioengineering professor David Gough and several GlySens researchers published results from the final study on a pair of pigs in the journal Science Translational Medicine.

Each pig was outfitted with the monitor, a titanium disc that measures just less than 1½ inches wide and just more than one-half inch thick. The devices, which were implanted just under the skin, worked successfully for 222 days in one animal and 520 days in the other.

If the device works well in people, it could revolutionize the way most diabetics manage their disease, several doctors said. With diabetes affecting about 24 million Americans, the monitor has the potential to become a blockbuster product.

“My impression would be that most physicians and patients would gravitate toward this system because it would be easier for them,” said Dr. Michael Gottschalk, a pediatric endocrinologist with Rady Children’s Hospital in San Diego.

No other research team is currently developing a similar device in the United States, said Dr. Guillermo Arreaza-Rubin, who oversees grants made by the National Institute of Diabetes and Digestion and Kidney Diseases for glucose sensing and insulin delivery research.

The GlySens monitor also exemplifies the convergence of medicine and cell phone technology, a burgeoning trend that promises to transform the way health care is delivered in the United States and around the world.

San Diego already is recognized as a leading hub of mobile health innovation, and GlySens’ work reinforces that potentially lucrative reputation.

The device uses sophisticated biology to measure glucose levels every two minutes and high-tech telemetry to beam the data out of the body to a portable receiver. A tiny battery similar to those used in implanted pacemakers provides enough power for at least two years of operation.

A special gel on one side of the monitor contains two types of enzymes that react with sugar molecules in the tissue just below the skin. The resulting chemical reactions produce oxygen, which is detected and measured by electronics inside the device. The amount of oxygen is then translated into a corresponding glucose level.

In humans, the monitor would be implanted just below the collarbone or in the lower abdomen during an outpatient procedure using local anesthesia and a few stitches to close up the small incision, Gough said. Initially, it would be replaced every year, but later generations of the device could last three years or longer.

The latest animal test is particularly encouraging because the tissue underlying the skin of pigs is very similar to subcutaneous tissue in humans, said Joseph Lucisano, a bioengineer and CEO of GlySens who co-authored the study.

The research leading up to the human trials request was mainly funded with grants from the National Institutes of Health, which includes the National Institute of Diabetes and Digestive and Kidney Diseases, and the Juvenile Diabetes Research Foundation.

Despite the promising results thus far, there’s no guarantee that the device will work well enough in people to win FDA approval.

Some significant questions about the sensor will have to be answered with further testing, said Gottschalk, who specializes in caring for children with diabetes.

“How far away can the receiver be from the transmitter?” he said. “How often do they give false alarms? How often do they just cut out?”

Replacing the monitor multiple times over the life span of a patient also could be troublesome if the body produces a tough protective shell of tissue around the device, said Eric Topol, a cardiologist with the Scripps Translational Science Institute and co-founder of the West Wireless Health Institute in San Diego.

For Gough, 63, the monitor is the culmination of his 3½ decades of work in the field.

“I’ve been working toward some form of glucose sensor for my entire career,” he said.

Gough founded GlySens with Lucisano in 1998. He continues to hold an ownership stake in the company and serves as a paid consultant.

Discovering a way to constantly track blood sugar levels has long been the Holy Grail of diabetes management.

People with diabetes don’t produce enough of the hormone insulin, which enables sugar, or glucose, to move from the blood stream into the body’s cells where it’s used as fuel. High blood-glucose levels can lead to eyesight problems, foot ulcers, nerve damage, kidney failure and high blood pressure.

Diabetics also run the risk of suffering from hypoglycemia, or a shortage of sugar in the blood, which can cause dizziness and confusion or, in the worst cases, seizures and life-threatening comas.

Most people resort to the pinprick method, which produces a drop of blood placed on a chemically treated strip that is analyzed by a small machine. But even among diabetics who check their blood three or four times a day, this approach misses large spans of time when blood-sugar levels can be too high or too low.

Over time, such fluctuations can lead to complications and take years off a person’s life.

Three continuous glucose-monitoring devices have been approved by the FDA, including one made by San Diego-based DexCom. However, they all work off thin wire sensors that must be inserted just under the surface of the skin and replaced at least once a week.

They also can stop working if they become dislodged or if the adhesive strips holding them in place become wet.

For those reasons, only several hundred thousand of the nation’s 24 million diabetics use those machines, Gough said.

The GlySens device represents a potentially major technological leap, Topol said. “If this really pans out in people, it’s a really big event.”

The company already has secured a $3 million grant from the National Institute of Diabetes and Digestive and Kidney Diseases and funding from investors to conduct the first study of the device in people, Lucisano said.

FDA approval to start the new round of research could come before the end of the year, he said.